Created
November 20, 2015 13:32
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Parser for a C-like language
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/* | |
Copyright (c) 2015 Simon Schmidt | |
This software is provided 'as-is', without any express or implied | |
warranty. In no event will the authors be held liable for any damages | |
arising from the use of this software. | |
Permission is granted to anyone to use this software for any purpose, | |
including commercial applications, and to alter it and redistribute it | |
freely, subject to the following restrictions: | |
1. The origin of this software must not be misrepresented; you must not | |
claim that you wrote the original software. If you use this software | |
in a product, an acknowledgement in the product documentation would be | |
appreciated but is not required. | |
2. Altered source versions must be plainly marked as such, and must not be | |
misrepresented as being the original software. | |
3. This notice may not be removed or altered from any source distribution. | |
*/ | |
package cparser | |
import "io" | |
import "strings" | |
import "github.com/maxymania/langtransf/syntaxfile" | |
import "github.com/maxymania/langtransf/parsing" | |
import "github.com/maxymania/langtransf/ast" | |
const rules = ` | |
/* BEGIN RULES */ | |
srcfile = (definition* #verbose EOF #mute) #precise; | |
type = Ident; | |
forParam = | |
~("Expr" expr) (","#- ~("Expr" expr))*; | |
paramlist = ~("PL" "("#- | |
( ~("P" type Ident) ~("P" ","#- type Ident)* )? | |
")"#- ) | |
; | |
definition | |
= ~("DV" type Ident ";"#- ) | |
| ~("DF" type Ident paramlist ";"#-) | |
| ~("F" type Ident paramlist stmblock) | |
; | |
exprlist | |
= "("#- ( ~("Px" expr) ~("Px" ","#- expr)* )? ")"#-; | |
unop = "-"|"~"|"!"; | |
binop | |
= ~("<<" "<" "<") | |
| ~(">>" ">" ">") | |
| ~("and" "&" "&") | |
| ~("or" "|" "|") | |
| ~("==" "=" "=") | |
| "+"|"-"|"*"|"/"|"%"|"<"|">"|"&"| "|" |"^" | |
; | |
expr0 | |
= Int | |
| Float | |
| Char | |
| String | |
| RawString | |
| ~("Call" Ident exprlist) | |
| Ident | |
| "("#- expr ")"#- | |
| ~("Unop" unop#E expr ) | |
; | |
expr1 | |
= ~("Op" binop expr0) | |
| ~("[]" "["#- expr "]"#-) | |
| ~(".Call" "."#- Ident exprlist) | |
| ~("." "."#- Ident) | |
| ~("=" "="#- expr) | |
; | |
expr = expr0 expr1*; | |
condition = ~("Cond" expr); | |
stmblock = ~("Code" "{"#- statement*#e "}"#E#- )#p; | |
switchCase | |
= ~("Case" "case"#- condition ":"#- statement*) | |
| ~("Default" "default"#- ":"#- statement*) | |
; | |
switchBlock = "{"#- switchCase* "}"#-; | |
statement =( | |
";"#-#E | |
| ~("DV" type#-#E Ident ";"#-) | |
| ~("If" "if"#-#E "("#- condition ")"#- ~("Then" statement) ~("Else" "else"#- statement)? ) | |
| ~("While" "while"#-#E "("#- condition ")"#- statement) | |
| ~("DoWhile" "do"#-#E statement "while"#- "("#- condition ")"#- ";"#- ) | |
| ~("While" "for"#-#E "("#- ~("Pre" forParam)? ";"#- condition? ";"#- ~("Post" forParam)? | |
")"#- statement ) | |
| ~("Switch" "switch"#-#E "("#- condition ")"#- switchBlock ) | |
| ~("Return" "return"#-#E expr? ";"#-) | |
| ~("Break" "break"#-#E ";"#-) | |
| ~("Continue" "continue"#-#E ";"#-) | |
| ("{"#E#- statement*#e "}"#E#- )#p | |
| ~("Expr" expr) ";"#- | |
)#e#p; | |
/* END RULES */ | |
` | |
var km = make(map[string]string) | |
var synfile syntaxfile.SyntaxFile = nil | |
func init(){ | |
synfile = syntaxfile.Parse(strings.NewReader(rules)) | |
synfile.ScanForKeyWords(km) | |
} | |
func Parse(src io.Reader) (*ast.AST,*syntaxfile.ErrorRecorder) { | |
a := new(ast.AST) | |
e := new(syntaxfile.ErrorRecorder) | |
s := new(parsing.StdScanner) | |
s.Init(km,src) | |
ft := s.FirstToken() | |
synfile["srcfile"].Parse(synfile,ft,a,e) | |
return a,e | |
} | |
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